Pegasia is as fertile as Earth, and its geography is more fragmented. Nine separate continents and many large islands will encourage species to diverge. But into what? What sort of critters will evolve here?

On second thought, I'm not sure all those seas will really do their job. On Earth, the sea's a barrier creating separate Petri dishes where new land animals evolve. But on Pegasia, with dense air and low gravity, quite large animals can fly. None of the continents is so deeply isolated that fliers couldn't cross the straits to it. So the average land animal's range will be determined more by ecological zones than coastlines. Maybe Pegasia won't be as diverse as I think!

What if it's as dull as Earth, with a single intelligent species dominating? Oh no!

One factor working for diversity is the fact that many of the continents are narrow yet span several latitude zones. Habitat varies from tropical to arctic. Jared Diamond's Pulitzer-winning book "Guns, Germs and Steel" argues that vertical arrangements like this promote splintered, tribal cultures, since crops and domestic animals (and cultural patterns themselves) don't readily transfer out of their own ecological zones. It took a thousand years to adapt Mexican maize to the strong seasons in the Mississippi Valley and points north. In contrast, east-west landmasses promote the spread of crops and technology: wheat flourished from China to Spain. So did trade--and empires.

Many of Pegasia's continents and clusters are more north-south. If Pegasians were flightless mammals as on Earth, we'd expect to see diverse cultures, maybe even more than one intelligent species. However, since conditions here favor fliers, civilization may be migratory, using each of several environments seasonally, as our birds do. If so, Pegasia may have a single intelligent species--maybe even just one worldwide race.

CULTURE

A world culture? I think local conditions vary so much this is unlikely, but a world trade-network (of light luxury items suitable for air transport; Earth-style shipping will likely develop more slowly) does seem plausible, and so does a worldwide trade-tongue. Anyone on a winged world can play Magellan. Indeed, circumnavigation (well, circumaviation) of Pegasia may be a normal rite of passage--flying a few hours a day, you'd only need a couple of months!

One people or many? I have an emotional bias toward the many-people pattern. First and foremost, it's just more fun. Also, I've decided to make Pegasia a cooperative endeavor on the Terran end: I'm offering ecological niches on Pegasia as a sort of prize to species-designers out there. Submit your species, name a continent, design a culture! So I'm biased toward allowing many intelligent species on the planet at once.

But I don't think my bias is terribly unscientific. It's not like we have a huge sample telling us how many species typically participate in civilizations around the Galaxy. Most worlds may be like ours, with one dominant species determined to go it alone (notice I do NOT say "one intelligent species evolving alone" since that's NOT the case on Earth. Several Terran species appear as smart as we are, and show strong evidence for true language: dolphins and several larger cetaceans and three species of elephants. Humans dominate for a cluster of reasons--hands, brains, sociability... need?) But for all we know, our solo pattern is rare. Many worlds may have shared civilizations, where several species adopt tools and language, if only to keep up with the neighbors. On other worlds, lone dominant species may breed companion peoples out of promising species, as David Brin suggests. Still other worlds may have habitats so different that intelligent species rarely meet, neither clashing nor competing, at least until late in civilization's development: for example, a world of giant parrots, subarctic brown bears (recent studies suggest high intelligence, close to that of chimps), air-breathing octopi on coral reefs, and whales in the deeps.